Low energy buildings are buildings that exhibit energy intensities below 15 ekWh/ft².yr (580 MJ/m².yr) in heating dominated climates. Such an energy intensity is approximately 50% below the typical energy intensity of existing commercial buildings.

This site provides information on design concepts to achieve low energy building designs through application of the Integrated Building Design (IBD) process. The principal focus of the site is on proper design and application of architectural elements, efficient lighting design and efficient HVAC systems to minimize building energy use.
The site is organized in eleven separate pages shown on the left sidebar. The topics that are covered range from a description of the IBD concept to design methods, illustrated through HVAC load calculations and energy simulations. The information presented is a compilation of research papers published by this author over a period of 15 years. The papers are available in pdf format in the “References & Further Reading” page and include three articles specific to IBD published in the ASHRAE Journal between 1996 and 2010 and additional papers presented at conferences.


Readers will find the introduction to the principles of the IBD process simple and straightforward compared to some of the complex language and intricate flowcharts available in the literature. The design approach presented here is based on the principle of load minimization and use of best-in-class technologies. This simple concept was initially described in the December 1996 ASHRAE paper available in the “References & Further Reading” page and follows Albert Einstein’s famous maxim:


Everything should be made as simple as possible, but not simpler.

The “Past Architecture” page links modern low energy buildings to architecture from the antiquity and some of the writings of the Roman Architect Vitruvious to show how today’s low energy buildings are going back to the design principles of the past, given that past architecture relied on daylighting, natural ventilation and other passive designs techniques; elements that are becoming trademarks of low energy buildings.


Building energy use data and metrics are included in the “Building Energy Use Statistics” page. This page references data from Canada, the U.S. and the European Union (EU) to illustrate the significant degree to which the “built-environment” contributes to the use of global energy resources. Energy end-use intensities (EUIs) from the U.S. Commercial Building Energy Consumption Survey (CBECS) and other sources are also included to show the relationship of individual end-uses to total building energy use. This information is used in later pages to prioritize the design techniques that can contribute to the largest reductions in energy use. EUIs are presented in MJ/m².yr  and  ekWh/ft².yr. The CBECS tables available in the 2003 ASHRAE HVAC Applications Handbook (SI Edition) present the data in MJ/m².yr and these values were converted to ekWh/ft².yr. There are also some statistical references that are presented in ekWh/m².yr. The energy intensities are always presented as site energy and no attempt is given to provide equivalent intensities at the source level.


Finally, the remainder of the website describes methods and techniques to achieve low energy designs. Design features are quantified via heating and cooling load calculations and energy simulations. Examples that are presented include illustrations of the energy use impact from optimization of architectural elements, as well as, efficient lighting design and HVAC design optimization.


© Copyright 2013 - 2020 Giuliano Todesco 



  • Low Energy Buildings – Transforming HVAC Design to an Art Painstakingly forging three hundred layers of steel. That is what it takes to create Damascus steel that exhibits legendary hardness, ease of sharpening and the characteristic patterned banding that gives Damascus steel its beauty. It is extreme craftmanship only possible with attention to detail.Low energy buildings share similarities. As a prerequisite towards net-zero and carbon neutral buildings, low energy buildings embody attention to detail, and a minimalist design elegance that can only emerge through application of a whole-systems approach to optimize the overall design. Amory Lovins [1] referred to this in a 2005 Scientific American article titled ‘More Profit with Less Carbon’ as:  “Good design should rely on optimizing the whole building for multiple benefits rather ...
    Posted Jul 12, 2020, 6:35 AM by
  • The Right Stuff to Achieve Truly Improved Building Energy Performance On Saturday July 20, I was having breakfast in the backyard, reading the newspaper. It was still early enough that the temperature was pleasant and the air fresh, unlike the furnace-like conditions that were expected later that afternoon.The newspaper had quite a few articles on the Apollo 11 mission in commemoration of the 50th Anniversary of the Moon Landing. One, written by Basil Hero, titled “Searching for the Right Stuff” struck a chord. Hero stated that one of the elements of “the right stuff” is the pursuit of the “common good”, which is rooted in ancient Greece where their citizens believed not in living just for themselves, but for the community. Towards the end of the article he ...
    Posted Jul 29, 2019, 6:11 AM by
  • Are Mainstream Low Energy Designs in the Horizon? The 2015 United Nations Climate Change Conference known as COP 21 that ended on December 12 reached its objective of a global agreement to reduce GHG emissions. It was hailed as a success even though it only becomes legally binding once it is signed by the 55-55 (the 55 nations that account for 55% of total GHG emissions). Critically though, the agreement calls for aggressively tackling GHG reductions immediately in order to reach Net Zero emissions in a couple of decades. Some readers will notice that this is more or less in line with the goals from ASHRAE, the 2030 Challenge and the EPBD from the European Union, although the EPBD target for reaching Net Zero is 2020. The ...
    Posted Feb 15, 2016, 6:40 AM by
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